Photocopying apparatus



K. J. WHITE 3,469,913

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ikzw-m United States Patent 3,469,913 PHGTOCOPYING APPARATUS Kenneth J. White, Framingham, Mass, assignor to Dennison Manufacturing Company, Framingham, Mass., a corporation of Nevada Continuation of application Ser. No. 337,477, Jan. 13, 1964, which is a continuation-in-part of application Ser. No. 263,804, Mar. 8, 1963. This application Apr. 10, 1967, Ser. No. 648,509

Int. Cl. G03!) 27/14 US. Cl. 35518 9 Claims ABSTRACT OF THE DISCLOSURE Apparatus comprising means for feeding a strip of copy material along a predetermined path, a cutter at one location along the path for cutting sheets from the strip, an exposure window at another location along the path in which the material is exposed, means for feeding different lengths of material to the cutter to produce either long or short sheets, the cutter being in advance of the window so that the sheets are cut before being exposed, and means for feeding the sheets from the cutter to the window so that both short and long sheets are centered in the window while being exposed.

This is a continuation of Ser. No. 337,477, filed Jan. 13, 1964, now abandoned, which was a continuation-inpart of Ser. No. 263,804, filed Mar. 8, 1963, now abandoned.

In one form of electrophotography or xerography, printing takes place on an insulating base such as paper to which has been applied a photoconductive coating such as zinc oxide. This coating is first electrostatically charged as for example by being passed through a corona discharge and is then exposed to a light image of the subject matter to be printed so that the electrostatic charge is locally dissipated thereby forming an electrostatic latent image. The latent image is developed by applying a toner which is electrostatically attracted and held by the portions of the image retaining a charge. The excess of toner is removed and the visible image is bonded to the base as for example by a thermoplastic resin.

Objects of the present invention are to provide control apparatus which prints sheets of different lengths, which can be set to the desired length quickly and easily, which automatically centers the sheets of diiferent lengths in the exposure position, and which permits the copier to operate rapidly without jamming.

According to this invention the apparatus comprises means for guiding a strip of copy material along a predetermined path, a separator disposed at one location along said path for separating sheets from the strip, an exposure window at another location along said path in which the copy material is exposed, means for feeding different lengths of material to the separator to produce eithershort or long sheets, the separator being in advance of the exposure window so that the sheets are cut before being exposed and feed means for feeding the sheets from the separator to the window so that both short and long sheets are centered in the window while being exposed. Preferably the apparatus has manual-settable means for controlling said feed means, and each sheet is stopped when centered in the exposure window.

In a preferred embodiment of the present invention the control apparatus comprises cyclically operative feed means for positioning printing material in an exposure area, an exposure timer, means for starting said exposure timer at the end of a feed cycle, a developing sequence timer, means for starting said developing timer at the end of an exposure, and means for preventing the recycling of said feed means until said developing sequence timer is started following an exposure.

For the purpose of illustration a preferred embodiment of the invention is shown in the accompanying drawings in which FIG. 1 is a perspective view showing the overall appearance of the printer;

FIG. 2 is a section substantially on the line 22 of FIG. 1 showing the internal arrangement of the printer;

FIG. 3 is a sectional view on enlarged scale showing the developing station;

FIG. 4 is a section substantially on the line 44 of FIG. 3;

FIG. 5 is a section on the line 5-5 of FIG. 4;

FIG. 6 is a plan view of the cam shaft visible in FIG. 2;

FIG. 7 is a section substantially on the line 7-7 of FIG. 2;

FIG. 8 is a diagrammatic illustration of the mechanical power flow in the apparatus illustrated in FIG. 2;

FIG. 9 is a schematic diagram of the circuitry for controlling the apparatus of FIG. 2; and

FIG. 10 is a diagrammatic illustration of the sequence in which switches are operated by the cam shaft of FIG. 6.

Referring now to FIG. 2 a transparent window 10 is provided for receiving the original record which is to be copied. The record is illuminated by lamps 12 which are arranged in cooperation with baflles 14 and light box 16 for providing essentially uniform illumination of the record. The construction of the light box is explained in greater detail in U.S. Patent 3,272,066, dated Sept. 13, 1966. An image of the record, formed by the lens 20, is reflected by a mirror 22 into exposure area 24.

Printing paper having a photoconductive coating is provided from a reel 26. The web of paper 27 from the reel passes first under a tensioning idler 28. This tensioning idler 28 is mounted on a lever arm 29 which is also arranged to operate a brake band 30 in conventional manner so as to prevent overrunning of the reel 26 caused by the intermittent drawing of the paper web. The web 27 passes from the idler roller 28 over a fixed idler 32 and then between a pair of driving rolls 34. Driving force for these rolls 34 and other parts of the mechanism is provided continuously by the geared down motor 36 through drive chains 37, 38 and 40 which extend to the appropriate portions of the apparatus. The sprocket 42, associated with the roll 34, is connected thereto through an electromagnetic clutch (not shown) which is energized intermittently according to a predetermined sequence by means which will be explained in greater detail hereinafter.

From the rolls 34 the paper web 27 passes through a cutting station 43 which includes a separator in the form of a knife 44 carried by a lever 45 and cooperating with an anvil 46 so as to be operable to cut the paper web 27.

From the cutting station 43 the web 27 passes through a corona discharge device 45 and between another set of driving rolls 47. The corona discharge device 45 is operative to charge the photoconductive layer on the paper web 27 in a manner conventional in the art prior to exposure. The driving rolls 47 also receive power from the associated sprocket 48 through an electromagnetic clutch (not shown) which is operated according to a predetermined sequence.

Leaving the rolls 47, the web passes into the exposure area 24. The web is carried through the exposure area by three elastic belts 50 which pass over fixed rollers 52 and tensioning rollers 54 and which are supported within the exposure area itself by a perforate backing plate 56 (FIG. 7). The web is held in contact with the belts 50 and substantially flat within the exposure area by a suction created by the blower 58 between the perforate backing plate 56 and plate 59.

From the exposure area 24 the web passes to a developing station 60 where a toner in liquid suspension is applied to the web. At the development station the web passes between three pairs of parallel rolls 62, 64 and 66. The first two pairs of rolls 62 and 64 are metal while the rolls 66 are constructed of a compliant material such as rubber suitable for squeegeeing the web. It has been found that, if the squeegeeing rolls are preceded by conductive rolls, the formation of a negative image on the back of the print is prevented. The lower roll of each pair is immersed in pan 67 of toner liquid. The pan 67 is provided with toner fluid by a pump 68 driven by electric motor 69. As illustrated, the pan 67 is resiliently supported on a lever arm 70, within a tank 72 of the toner fluid within which the pump 68 is submerged. The lever arm 70 is urged upward by a spring 74. In this way the pan can be depressed out of engagement with the rolls for removal.

The lower roll of each pair carries a film of the toner liquid upwards toward the coated face of the web 27 (FIG. 5) where the electrostatic image thereupon is developed by attracting the toner material suspended in the liquid. The rolls are, as seen in FIG. 4, substantially longer than the web 27 is wide. By this arrangement the fillet 65 of toner liquid which tends to work its way inwardly from the ends of the rolls on the downstream side is prevented from wetting the edge of the squeegeed web.

After leaving the developing station the paper web is led, by a curved guide 90, between a pair of heat lamps 92 which dry the developed print. The guide 90 deposits the finished print on moving belts 93 and 94 which lead the print to a pair of opposed moving belts 96 and 97 which in turn deposit the print in the finished print receptacle 100.

The motor 36 also powers, through chain drive 38, a cam shaft 102. An electrically controlled, one-revolution clutch 104 is interposed between the cam shaft and its associated sprocket 106. A plurality of cams 111-115 on the shaft 102 operate corresponding microswitches M1- M5 which control the operations of the various parts of the printer according to a predetermined sequence which will be discussed in detail hereinafter with respect to FIG. 9. The shaft 102 also carries a cam 130 which cooperates with a follower 132 on the lever 45 so as to operate the web-cutting knife 44.

FIG. 8 illustrates in diagrammatic form the flow of mechanical energy from the motor 36 to the various parts of the mechanism illustrated in FIG. 2. The motor 36 is provided with an integral gear box 36.1. A chain drive 38 provides a further reduction in speed to the cam shaft 102. The cam shaft is provided with a one-revolution clutch 104 and carries a knife actuating cam 130 and cams for actuating five microswitches Ml-MS. A preset print counter 140 is driven from the cam shaft 102 through 16:1 gearing 138 and a friction clutch 139. The friction clutch allows the counter to be set to any desired number of prints and as the printing proceeds the counter is backed down to zero at which point a switch S6 is opened to stop recycling. While any well-known counter may be employed, the counter disclosed in my application Ser. No. 508,347, filed Nov. 17, 1965, is preferred. The motor 36 also drives, through chain drive 37, the rolls 34 which feed the paper web to the knife 44, the rolls 47 and belts 50 which pass the paper through the exposure station, and the developing station 60. Each of the feed systems is provided with a magnetic clutch K2 and K3 respectively, which permits them to be operated in the desired sequence.

The sequence of operations is controlled by the circuitry shown in FIG. 9. The apparatus is connected to power mains through a main switch S10 and safety interlock switches S11 and S12. The interlock switches are arranged so as to be opened when the cabinet is opened.

The timing portions of the circuit are protected by a fuse F while the heavier load of the drying heaters 92 is supplied directly from the line so that the fuse F may be more sensitive to malfunctions in the timing circuitry. The main driving motor 36, the blower 58 and the pump 68- 69 and pilot light 7 are arranged soas to be on continuously when the main switch S10 is thrown.

The sequence of operations is as follows, reference being had to the circuit diagram of FIG. 9 in which all switches, timer contacts and relays are shown in their normal positions, that is with the apparatus at rest. Operation is initiated by momentarily throwing switch S1 which is a double-throw pushbutton switch visible in FIG. 1. This energizes the coil K1 of the one-revolution clutch 104 thereby initiating rotation of the cams 111-115 so as to actuate the microswitches M1-M5. A switch S2, which is arranged so as to be responsive to the presence of paper on reel 26, is interposed in this circuit to prevent operation of the printer when no paper is available. The apparatus illustrated is arranged to produce either of two sizes of prints, eleven inches long or fourteen inches long, and the choice between these two sizes is made by operating the double-pole double-throw switch S3A-S3B. The switch is illustrated as being in the eleven inch position. The sequence in which the microswitches M1-M5 are operated by the cams 111-115 is illustrated in FIG. 10. The first of the microswitches to be actuated are M4 and M5 which connect the actuating coil K3 of the clutch on the driving rolls 47 (FIG. 2) in series with the switch M3 so that when the switch M3 is actuated shortly thereafter, the rolls 47 and the belts 50 which are geared thereto, begin to move. At this point however no part of the paper web will be in contact with either the rolls 47 or the belt 50. The switch M3 also starts the corona discharge device 45.

When the switch S3A set for eleven inch prints, the next operation having any effect is the actuation of microswitch M1 which energizes the actuating coil K2 for the clutch controlling the operation of the rolls 34. These rolls then start to feed the paper web through the cutting station 43 and through the corona discharge device 45 where the photoconductive coating on the web is sensitized by being electrostatically charged. Relay coils K2 and K3 are provided with direct current by the diode D1.

After the passage of time sutficient to allow the eleven inches of the paper web to pass through the cutting station 43 the switch M1 is opened thereby stopping the feed to the knife. The cam which controls the knife 44 is shaped so that the knife is operated simultaneously with the stopping of the rolls 34 so that the portion of the web being drawn by the rolls 47 proceeds evenly and without interruption through the corona discharge device 45 and accordingly is given a uniform surface charge.

To produce fourteen inch prints the switch 53A is moved to its right-hand position (FIG. 9) thereby shifting the control from cam M1 to cam M2 and, as shown in FIG. 10, this causes a longer length of paper to be fed past the cutter before the cutter operates.

The cutoff portion of the paper web is carried forward by the rollers 47 and the belts 50 to the exposure station 24, the operations of the switches M4 and M5 being timed by the respective cams so as to stop the movement of the belts 50 when the cutoff portion of the web is exactly centered within the exposure area. With switch S3B in the left-hand position (FIG. 9) the feed of the cut sheet to the exposure position is controlled by cam M4 (FIG. 8) which energizes clutch K2 long enough to bring the eleven inch sheet to the center of the exposure position (FIG. 10) and with the switch S3B in the right-hand position (FIG. 9) the feed of the cut sheet to the exposure position is controlled by cam M5 (FIG. 8) which energizes clutch K3 long enough to bring the fourteen inch sheet to the center of the exposure position (FIG. 10).

The return of the switch M4 to its original position while the microswitch M3 is still actuated, provides power to an adjustable exposure timer T1. Relays R1 and R2 are energized simultaneously with the timer T1. Relay contacts RlA operating through timer contacts TIA, set up a holding circuit for the timer T1 and relay contacts RIB turn off the corona discharge device 45. Relay contacts R2A and R2B turn on the exposure lamps 12. The lamps 12 are protected from overheating by thermostats 13. Shortly after the exposure has begun the microswitch M3 is returned to its original position, the operation of the timer T1 being sustained through its hold ing circuit. It should be noted that, although the cam shaft cycle ends shortly after the release of microswitch M3, a new cycle cannot be initiated during the exposure period since the operation of the relay contacts RlA to form the exposure timer holding circuit also disconnects the cam shaft clutch energizing coil K1 from its source of power.

Shortly before the end of the exposure period timer contacts TlB are closed by timer T1 energizing development timer T2. Separate timers are utilized for the exposure and development processes so that they may occur simultaneously on different severed sheets. Relay R3 is actuated simultaneously with timer T2 and relay contacts RSA and R3B energize the print drying heaters 92. These heaters are also protected by thermostats 91. Before the approaching end of the exposure timer contacts T2A are closed to form a holding circuit for sustaining the operation of the development timer T2. The exposure period ends when timer contacts TIA are opened by exposure timer T1, breaking the exposure timer holding circuit and opening relay contacts R2A and R2B to turn off the exposure lamps 12. Timer T1 is preferably of the well-known type which returns to zero position when its circuit is broken at T1A. After delaying long enough to allow the exposure to finish, the development timer T2 closes its contacts T2B thereby restarting the belts 50 so as to pass the exposed print from the exposure station 24 into the development station 60. These contacts TZB are reopened after the print has left the exposure station 24 so that the operation of the belts 50 can be controlled by the microswitches M4 and M5 in a manner appropriate for handling and centering a new portion of the paper web..

Switch S6 is operated by the preset print counter 140 and its contacts are open when the counter indicates zero. By setting the counter to higher numbers the printer will be caused to produce a corresponding number of prints from a given record, the initiating function of the switch S1 being bypassed by the switch S6. Since S6 can, however, draw power only through either development timer contacts T2A or exposure timer contacts T1B, the printers operation will not be initiated when the counter is preset although the contacts S6 will maintain the operation for a selected number of prints once operation is initiated by means of S1.

The following is a summary of the sequence of operations during each operation.

The counter 140 is set for the desired number of prints. For short prints switches 83A and S3B are left in the left-hand positions shown in FIG. 9 and for long prints these switches are manually shifted to the righthand position.

Then switch S1 is closed momentarily to energize one-revolution clutch K1 to start shaft 102. If only one print is desired the counter need not be set and the clutch throws out automatically at the end of one revolution of the shaft. If a number of prints is desired the counter is set for that number and the counter opens switch S6 during the last revolution of that number so that at the end of that revolution the clutch throws out automatically.

As shaft 102 starts to turn it first moves switches M4 and MS from left to right (FIGS. 9 and 10). Then when M3 closes, the corona is started and K3 starts the exposure feed 4750 (FIG. 2).

Next M1 or M2 energizes K2 to start the supply feed 34. After the desired length of copy material 27 has been fed past the cutter 43, M1 and M2 open to stop the supply feed and the cutter is actuated by cam to cut off the selected length. The exposure feed 47-50, which has already been started, continues the advance of the cut-off sheet to the exposure position 24 (FIG. 2).

When the sheet is centered in the exposure position switches M4 and M5 move back to the left-hand position, thereby (1) de-energizing K3 to stop the exposure feed 47-50, (2) starting exposure timer T1 (3) energizing R1 to move switch RlA down to establish a holding circuit through TIA and (4) energizing R2 to turn on the exposure lights 12 by closing switches R2A and R2B. The movement of switch R1A to its lower position also opens the circuit to clutch K1 so that it stops the shaft 102 at the end of the current cycle.

M3 opens shortly after the exposure begins, thereby stopping the corona discharge.

Timer T1 closes switch TlB shortly before the end of each exposure to start the developer timer T2.

Timer T2 closes switch T2A to establish a holding circuit for T2.

Timer T1 opens TIA thereby (1) opening the circuit of T1 and permitting it to return to zero position, (2) opening the circuit of R1 and permitting switch RlA to return to its upper position so that a subsequent cycle of cam shaft 102 can be initiated through K1 and (3) opening the circuit of R2 to turn off lights 12 by opening R2A and R2B.

Exposure timer T2 closes switch T2B to energize K3 and restart the exposure feed 47-50 to clear the exposure position before a new sheet can be fed to the exposure position in a succeeding cycle initiated by closing S1 to energize K1 through RlA. Thus switch RlA, controlled by timer T2 which in turn is controlled by timer T1, constitutes means preventing the supply feed means 34 from feeding a succeeding sheet to the exposure position before the exposure feed means 47-50 starts the exposed sheet from the exposure position,

After the sheet has been fed from the exposure position to the developer 60 (FIG. 2), T2 opens T2B to stop the exposure feed 47-50.

Timer T2 then opens switch T2A to stop itself. This timer is preferably of the well known type which makes one complete revolution per cycle and then continues in the same direction during the next cycle.

While a particular embodiment has been shown by way of illustration, it should be understood that the present invention includes all modifications and equivalents falling within the scope of the appended claims.

I claim:

1. Photocopy apparatus of the type having means for guiding a strip of copy material along a predetermined path, a separator disposed at one location along said path for separating sheets from the strip, an exposure window at another location along said path in which the copy material is exposed, exposure means including an optical system for projecting images to said window along a fixed optical axis, first means for feeding sheets to the separator, the separator being in advance of the exposure window so that the sheets are cut before being exposed, second means for feeding the sheets from the separator to the Window through a position centered on said axis, preset means for selection of one of different sheet lengths, and control means responsive to said preset means to cause the separator to produce sheets of the selected length and to cause said second means to move said sheets to centered position and then to actuate said exposure means.

2. Photocopying apparatus according to claim 1 further characterized by manual-settable means for controlling said last means.

3. Photocopying apparatus according to claim 1 further characterized in that each sheet is stopped when centered in the exposure window.

4. Photocopying apparatus comprinsing means for guiding a strip of copy material along a predetermined path, a cutter at one location along said path for cutting oif sheets of said material from said strip, first means to feed said strip to said location, an exposure position at another location farther along said path for exposing said sheets successively, first control means for stopping said first feed means and actuating said cutter when a predetermined length of material has passed the cutter, means for setting said first control means to a plurality of positions for diiferent lengths of sheet, second means to feed each sheet from the cutter to the exposure position, and second control means for stopping said second feed means when sheets of said diiferent lengths are centered in said exposure position.

5. Photocopying apparatus according to claim 4 further characterized in that said setting means conjointly shifts said first and second control means from one length to another.

6. Photocopying apparatus according to claim 4 wherein said control means comprises timers operative through one cycle for each sheet.

7. Photocopying apparatus according to claim 6 wherein said timers are operated by a shaft which makes one revolution during each cycle.

8. Photocopying apparatus according to claim 4 further characterized by means preventing said first feed means from feeding a succeeding sheet to the exposure position before the second feed means starts the exposed sheet from the exposure position.

9. Photocopying apparatus comprising means for guiding a strip of copy material along a predetermined path, a cutter at one location along said path for cutting 01f sheets of material from said strip, first means for feeding said strip to said first location, an exposure position at another location farther along said path for exposing said sheets successively, first control means for stopping said first feed means and actuating said cutter when a predetermined length of material has passed the cutter, second means to feed each sheet from the cutter to the exposure position, second control means for stopping said second feed means when each cut-off sheet is centered in said exposure position, and means preventing said first feed means from feeding a succeeding sheet to the exposure position before the second feed means starts the exposed sheet from the exposure position.

References Cited UNITED STATES PATENTS JOHN M. HORAN, Primary Examiner 

